Finance Receivables - Schedule of FICO Score (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total finance receivables	$ 3,971.1	$ 3,348.7
Auto Loan Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Current year	1,675.4	1,707.2
Fiscal year before current fiscal year	1,173.3	1,188.6
Two years before current fiscal year	782.7	248.9
Three years before current fiscal year	148.7	27.1
Four years before current fiscal year	14.2
Total finance receivables	3,794.3	3,171.8
Other Finance Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Total finance receivables	176.8	176.9
Less than 599 \| Auto Loan Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Current year	53.0	62.2
Fiscal year before current fiscal year	39.7	39.0
Two years before current fiscal year	22.4	17.6
Three years before current fiscal year	9.9	2.4
Four years before current fiscal year	1.4
Total finance receivables	126.4	121.2
FICO Score, 600 to 699 \| Auto Loan Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Current year	534.1	586.6
Fiscal year before current fiscal year	406.2	463.6
Two years before current fiscal year	298.8	152.7
Three years before current fiscal year	90.2	16.1
Four years before current fiscal year	8.3
Total finance receivables	1,337.6	1,219.0
FICO Score, 700 to 774 \| Auto Loan Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Current year	560.2	568.1
Fiscal year before current fiscal year	402.5	422.5
Two years before current fiscal year	284.9	63.9
Three years before current fiscal year	39.5	5.9
Four years before current fiscal year	3.2
Total finance receivables	1,290.3	1,060.4
FICO Score, Greater than 775 \| Auto Loan Receivables
Financing Receivable, Excluding Accrued Interest, before Allowance for Credit Loss, by Origination Year [Abstract]
Current year	528.1	490.3
Fiscal year before current fiscal year	324.9	263.5
Two years before current fiscal year	176.6	14.7
Three years before current fiscal year	9.1	2.7
Four years before current fiscal year	1.3
Total finance receivables	$ 1,040.0	$ 771.2

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- Definition

Amortized cost excluding accrued interest, before allowance for credit loss, of financing receivable classified as noncurrent. Excludes net investment in lease.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 326
-SubTopic 20
-Name Accounting Standards Codification
-Section 45
-Paragraph 1
-Publisher FASB
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Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 326
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-Section 55
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Amortized cost excluding accrued interest, of financing receivable originated three years prior to current fiscal year. Excludes net investment in lease.

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Amortized cost excluding accrued interest, of financing receivable originated two years prior to current fiscal year. Excludes net investment in lease.

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